Q: Is 645,821 a Prime Number?
A: No, 645,821 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 645821 can be evenly divided by 1 11 58,711 and 645,821, with no remainder.
Since 645,821 cannot be divided by just 1 and 645,821, it is not a prime number.